scholarly journals Broadband SERS detection with disordered plasmonic hybrid aggregates

Nanoscale ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 93-102 ◽  
Author(s):  
Peng Mao ◽  
Changxu Liu ◽  
Qiang Chen ◽  
Min Han ◽  
Stefan A. Maier ◽  
...  
Keyword(s):  
Field Enhancement ◽  
Plasmonic Nanostructures ◽  
Large Area ◽  
Plasmonic Device ◽  
Intense Field ◽  
Sers Detection ◽  
Device Applications

Plasmonic nanostructures possessing broadband intense field enhancement over a large area are highly desirable for nanophotonic and plasmonic device applications.

scholarly journals Ultra-high-Q resonances in plasmonic metasurfaces

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
M. Saad Bin-Alam ◽  
Orad Reshef ◽  
Yaryna Mamchur ◽  
M. Zahirul Alam ◽  
Graham Carlow ◽  
...  
Keyword(s):  
Incident Light ◽  
Reducing Power ◽  
Field Enhancement ◽  
Plasmonic Nanostructures ◽  
High Q ◽  
Alternative Material ◽  
Order Of Magnitude ◽  
Wavelength Scale ◽  
Strong Confinement ◽  
Sub Wavelength

AbstractPlasmonic nanostructures hold promise for the realization of ultra-thin sub-wavelength devices, reducing power operating thresholds and enabling nonlinear optical functionality in metasurfaces. However, this promise is substantially undercut by absorption introduced by resistive losses, causing the metasurface community to turn away from plasmonics in favour of alternative material platforms (e.g., dielectrics) that provide weaker field enhancement, but more tolerable losses. Here, we report a plasmonic metasurface with a quality-factor (Q-factor) of 2340 in the telecommunication C band by exploiting surface lattice resonances (SLRs), exceeding the record by an order of magnitude. Additionally, we show that SLRs retain many of the same benefits as localized plasmonic resonances, such as field enhancement and strong confinement of light along the metal surface. Our results demonstrate that SLRs provide an exciting and unexplored method to tailor incident light fields, and could pave the way to flexible wavelength-scale devices for any optical resonating application.

scholarly journals Shape-Controlled, Single-Crystal Gold Surface Nanostructures

2019 ◽  
Author(s):  
Sasan V. Grayli ◽  
Xin Zhang ◽  
Dmitry Star ◽  
Gary Leach
Keyword(s):  
Single Crystal ◽  
Electroless Deposition ◽  
Near Field ◽  
Critical Role ◽  
Deposition Process ◽  
Local Fields ◽  
Metal Nanostructures ◽  
Large Area ◽  
Device Applications ◽  
Shape Controlled

Size, shape and crystallinity play a critical role in the wavelength-dependent optical responses and plasmonic local near-field distributions of metallic nanostructures. While their enhanced local fields can drive new and useful chemical and physical processes, the ability to fabricate shape-controlled single-crystal metal nanostructures and position them precisely on substrates for device applications represents a significant barrier to harnessing their greater potential. Here, we describe a novel electroless deposition process in the presence of anionic additives that yields additive-specific, shape-controlled, single-crystal plasmonic Au nanostructures on Ag(100) and Au(100) substrates. Deposition of Au in the presence of SO<sub>4</sub><sup>2-</sup> ions results in the formation of smooth Au(111)-faceted square pyramids that show large surface enhanced Raman responses. The use of halide additives such as Cl<sup>-</sup> and Br<sup>- </sup>that interact strongly with (100) facets produces highly textured hillock-type structures characterized by edge and screw-type dislocations (Cl<sup>-</sup>), or flat platelet-like features characterized by large area Au(100) terraces with (110) step edges (Br<sup>-</sup>). Use of additive combinations provides structures that comprise characteristics derived from each additive including new square pyramidal structures with dominant Au(110) facets (SO<sub>4</sub><sup>2-</sup>and Br<sup>-</sup>). Finally we demonstrate that this bottom-up electroless deposition process, when combined with top-down lithographic patterning methods, can be used to position shape-controlled, single-crystal Au nanostructures with precise location and orientation on surfaces. We anticipate that this approach will be employed as a powerful new tool to tune the plasmonic characteristics of nanostructures and facilitate their broader integration into device applications.

scholarly journals Methods for measuring the local emission characteristics of CNT based multi-tip emitters

2021 ◽  
Vol 2103 (1) ◽  
pp. 012116
Author(s):  
E O Popov ◽  
A G Kolosko ◽  
S V Filippov ◽  
S A Ponyaev
Keyword(s):  
Enhancement Factor ◽  
Field Enhancement ◽  
Emission Characteristics ◽  
Large Area ◽  
Software Complex ◽  
Emission Area ◽  
Current Voltage ◽  
Local Emission ◽  
Current Voltage Characteristics ◽  
Comparison Of The Results

Abstract The work is aimed at obtaining microscopic emission characteristics of individual emission sites of a multi-tip field cathode or large-area emitter (LAFE) based on processing the current-voltage characteristics and emission glow patterns. Processing was carried out on a hardware-software complex for the study of field emission characteristics in real time. The calculation of the microscopic characteristics of the local emission sites — the field enhancement factor and emission area — was carried out by several different algorithms. A comparison of the results showed that the algorithms gave close values of the characteristics, which increases the reliability of the estimates made.

scholarly journals Metal–dielectric hybrid nanoantennas for efficient frequency conversion at the anapole mode

2018 ◽  
Vol 9 ◽  
pp. 2306-2314 ◽  
Author(s):  
Valerio F Gili ◽  
Lavinia Ghirardini ◽  
Davide Rocco ◽  
Giuseppe Marino ◽  
Ivan Favero ◽  
...  
Keyword(s):  
Frequency Conversion ◽  
Near Infrared ◽  
Strong Field ◽  
Second Harmonic ◽  
Near Field ◽  
Field Enhancement ◽  
High Refractive Index ◽  
Plasmonic Nanostructures ◽  
Ohmic Losses ◽  
Order Of Magnitude

Background: Dielectric nanoantennas have recently emerged as an alternative solution to plasmonics for nonlinear light manipulation at the nanoscale, thanks to the magnetic and electric resonances, the strong nonlinearities, and the low ohmic losses characterizing high refractive-index materials in the visible/near-infrared (NIR) region of the spectrum. In this frame, AlGaAs nanoantennas demonstrated to be extremely efficient sources of second harmonic radiation. In particular, the nonlinear polarization of an optical system pumped at the anapole mode can be potentially boosted, due to both the strong dip in the scattering spectrum and the near-field enhancement, which are characteristic of this mode. Plasmonic nanostructures, on the other hand, remain the most promising solution to achieve strong local field confinement, especially in the NIR, where metals such as gold display relatively low losses. Results: We present a nonlinear hybrid antenna based on an AlGaAs nanopillar surrounded by a gold ring, which merges in a single platform the strong field confinement typically produced by plasmonic antennas with the high nonlinearity and low loss characteristics of dielectric nanoantennas. This platform allows enhancing the coupling of light to the nanopillar at coincidence with the anapole mode, hence boosting both second- and third-harmonic generation conversion efficiencies. More than one order of magnitude enhancement factors are measured for both processes with respect to the isolated structure. Conclusion: The present results reveal the possibility to achieve tuneable metamixers and higher resolution in nonlinear sensing and spectroscopy, by means of improved both pump coupling and emission efficiency due to the excitation of the anapole mode enhanced by the plasmonic nanoantenna.

Manipulating the directional emission of monolayer semiconductors by dielectric nanoantenna arrays

2021 ◽  
Author(s):  
Pengbo Liu ◽  
Zhenghe Zhang ◽  
Man Lang ◽  
Wanli Lu ◽  
Ping Bai ◽  
...  
Keyword(s):  
Strong Field ◽  
Field Enhancement ◽  
Poor Quality ◽  
Large Area ◽  
Light Emitting Devices ◽  
Directional Emission ◽  
Si Nanoparticle ◽  
High Efficient ◽  
Efficient Scheme ◽  
Different Diameters

Abstract Collective Mie resonances in silicon (Si) nanoparticle arrays (NPAs) feature low absorption losses and strong field enhancement extending to a large area. They provide a high-efficient scheme to manipulate the emission properties of monolayer semiconductors. However, the poor quality factor of the current reported Si NPA limits the performance of light-emitting devices. It is mainly due to the constituent materials of nanoparticles being amorphous or polycrystalline silicon, which have higher absorption coefficients in comparison with monocrystalline silicon (c-Si) among the visible band. This invited paper demonstrates a versatile technique to integrate the atomic layers onto the c-Si NPA. We show that our method can fully preserve the monolayer sample. We further investigate the directional emission tailored by the NPA with different diameters by combining back-focal-plane imaging and reciprocity simulations. The flexible tune of the geometry parameters of NPAs can offer many possibilities to control and manipulate the emission from monolayer semiconductors by engineering their photonic environments.

Photoelectron Spectroscopic Imaging and Device Applications of Large-Area Patternable Single-Layer MoS2Synthesized by Chemical Vapor Deposition

ACS Nano ◽  
2014 ◽  
Vol 8 (5) ◽  
pp. 4961-4968 ◽  
Author(s):  
Woanseo Park ◽  
Jaeyoon Baik ◽  
Tae-Young Kim ◽  
Kyungjune Cho ◽  
Woong-Ki Hong ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Single Layer ◽  
Chemical Vapor ◽  
Spectroscopic Imaging ◽  
Large Area ◽  
Device Applications

scholarly journals Imaging of local structures affecting electrical transport properties of large graphene sheets by lock-in thermography

2019 ◽  
Vol 5 (2) ◽  
pp. eaau3407 ◽  
Author(s):  
H. Nakajima ◽  
T. Morimoto ◽  
Y. Okigawa ◽  
T. Yamada ◽  
Y. Ikuta ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Chemical Vapor ◽  
Atomic Scale ◽  
Electrical Transport Properties ◽  
Large Area ◽  
Graphene Layers ◽  
Device Applications ◽  
Chemical Vapor Deposition Graphene ◽  
Lock In

The distribution of defects and dislocations in graphene layers has become a very important concern with regard to the electrical and electronic transport properties of device applications. Although several experiments have shown the influence of defects on the electrical properties of graphene, these studies were limited to measuring microscopic areas because of their long measurement times. Here, we successfully imaged various local defects in a large area of chemical vapor deposition graphene within a reasonable amount of time by using lock-in thermography (LIT). The differences in electrical resistance caused by the micrometer-scale defects, such as cracks and wrinkles, and atomic-scale domain boundaries were apparent as nonuniform Joule heating on polycrystalline and epitaxially grown graphene. The present results indicate that LIT can serve as a fast and effective method of evaluating the quality and uniformity of large graphene films for device applications.

scholarly journals Tunable Memristic Characteristics Based on Graphene Oxide Charge-Trap Memory

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 151 ◽  
Author(s):  
Lei Li
Keyword(s):  
Graphene Oxide ◽  
Electron Microscope ◽  
Indium Tin Oxide ◽  
Nonvolatile Memory ◽  
Nanocomposite Films ◽  
Large Area ◽  
Charge Trap ◽  
Nonvolatile Memory Devices ◽  
Device Applications ◽  
Sandwiched Structure

Solution-processable nonvolatile memory devices, consisted of graphene oxide (GO) embedded into an insulating polymer polymethyl methacrylate (PMMA), were manufactured. By varying the GO content in PMMA nanocomposite films, the memristic conductance behavior of the Ni/PMMA:GO/Indium tin oxide (ITO) sandwiched structure can be tuned in a controllable manner. An investigation was made on the memristic performance mechanism regarding GO charge-trap memory; these blends were further characterized by transmission electron microscope (TEM), scanning electron microscope (SEM), Fourier transform infrared spectra (FTIR), Raman spectra, thermogravimetric analysis, X-ray diffraction (XRD), ultraviolet-visible spectroscopy, and fluorescence spectra in particular. Dependent on the GO content, the resistive switching was originated from the charges trapped in GO, for which bipolar tunable memristic behaviors were observed. PMMA:GO composites possess an ideal capability for large area device applications with the benefits of superior electronic properties and easy chemical modification.

scholarly journals Cost-Effective and High-Throughput Plasmonic Interference Coupled Nanostructures by Using Quasi-Uniform Anodic Aluminum Oxide

Coatings ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 420 ◽  
Author(s):  
Bae ◽  
Yu ◽  
Jung ◽  
Lee ◽  
Choi
Keyword(s):  
Aluminum Oxide ◽  
High Throughput ◽  
Anodic Aluminum Oxide ◽  
Noble Metals ◽  
Cost Effective ◽  
Plasmonic Nanostructures ◽  
Large Area ◽  
Plasmonic Material ◽  
Anodic Aluminum ◽  
The Cost

Large-area and uniform plasmonic nanostructures have often been fabricated by simply evaporating noble metals such as gold and silver on a variety of nanotemplates such as nanopores, nanotubes, and nanorods. However, some highly uniform nanotemplates are limited to be utilized by long, complex, and expensive fabrication. Here, we introduce a cost-effective and high-throughput fabrication method for plasmonic interference coupled nanostructures based on quasi-uniform anodic aluminum oxide (QU-AAO) nanotemplates. Industrial aluminum, with a purity of 99.5%, and copper were used as a base template and a plasmonic material, respectively. The combination of these modifications saves more than 18 h of fabrication time and reduces the cost of fabrication 30-fold. From optical reflectance data, we found that QU-AAO based plasmonic nanostructures exhibit similar optical behaviors to highly ordered (HO) AAO-based nanostructures. By adjusting the thickness of the AAO layer and its pore size, we could easily control the optical properties of the nanostructures. Thus, we expect that QU-AAO might be effectively utilized for commercial plasmonic applications.

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